Effects of tebufenozide on ovarian growth and sexual behavior in the German cockroach (Blattella germanica).

Tebufenozide, a dibenzoylhydrazine insect growth regulator, was applied topically (1 microg/insect) on female adults of the German cockroach Blattella germanica and its effects on ovarian measurement and proteins contents were investigated during the first gonadotrophic cycle (0, 2, 4 and 6 days). Dissection of treated females showed a clear reduction in oocyte numbers and volume of the basal oocyte. The ovarian proteins content was also significantly reduced. Behavioral tests demonstrated that treatment of 6-days-old females with tebufenozide caused in 80% of the males an increase in numbers of antennal contacts, but there was no effect on the numbers of wing raisings. In contrast, it was striking that in 20% of the males there was a total loss of antennal contacts and wings raisings in response to a calling treated female. These behavior effects are probably caused by a reduced production of contact sex pheromone in the females and may help in explaining the lower ovary reproductive parameters.